Lock



FIG. 1 is a perspective view of a lock showing our new design;

FIG. 2 is a top view of the lock shown in FIG. 1;

FIG. 3 is a front view of the lock shown in FIG. 1, the back view being a mirror image;

FIG. 4 is a side view of the lock shown in FIG. 1, the other side being a mirror image; and,

FIG. 5 is a bottom view of the lock shown in FIG. 1.

The broken lines, which define the bounds of the claimed design form no part thereof. The broken lines environmental are for illustrative purpose only and form no part pf the claimed design. 

The ornamental design for a lock, as shown and described. 